A protocol for periprosthetic joint infections from the Northern Infection Network for Joint Arthroplasty (NINJA) in the Netherlands.

Periprosthetic joint infection (PJI) is a devastating complication of joint arthroplasty surgery. Treatment success depends on accurate diagnostics, adequate surgical experience and interdisciplinary consultation between orthopedic surgeons, plastic surgeons, infectious disease specialists and medical microbiologists. For this purpose, we initiated the Northern Infection Network for Joint Arthroplasty (NINJA) in the Netherlands in 2014. The establishment of a mutual diagnostic and treatment protocol for PJI in our region has enabled mutual understanding, has supported agreement on how to treat specific patients, and has led to clarity for smaller hospitals in our region for when to refer patients without jeopardizing important initial treatment locally. Furthermore, a mutual PJI patient database has enabled the improvement of our protocol, based on medicine-based evidence from our scientific data. In this paper we describe our NINJA protocol.Level of evidence: III.

Influence of gender on the performance of urine dipstick and automated urinalysis in the diagnosis of urinary tract infections at the emergency department.

BACKGROUND: Urinary tract infections (UTIs) are frequently encountered at the Emergency Department (ED). Given the anatomical differences between men and women, we aimed to clarify differences in the diagnostic performance of urinary parameters at the ED. METHODS: A cohort study of adults presenting at the ED with fever and/or clinical suspected UTI. Performance of urine dipstick (UD) and automated urinalysis (UF-1000i) were analysed for the total study population and men and women separately. We focused on 1) UTI diagnosis and 2) positive urine culture (UC, ≥105 CFU/ml) as outcome. RESULTS: In 360 of 917 cases (39.3%) UTI was established (men/women 35.1%/43.6%). Diagnostic accuracy of UD was around 10% lower in women compared to men. Median automated leucocyte and bacterial count were higher in women compared to men. Diagnostic performance by receiver operating analysis was 0.851 for leucocytes (men/women 0.879/0.817) and 0.850 for bacteria (men/women 0.898/0.791). At 90% sensitivity, cut-off values of leucocyte count (men 60/µL, women 43/µL), and bacterial count (men 75/µL, women 139/µL) showed performance differences in favour of men. In both men and women, diagnostic performance using specified cut-off values was not different between normal and non-normal bladder evacuation. UC was positive in 327 cases (men/women 149/178), as with UTI diagnosis, diagnostic values in men outperformed women. CONCLUSIONS: Overall diagnostic accuracy of urinary parameters for diagnosing UTI is higher in men. The described differences in cut-off values for leukocyte and bacterial counts for diagnosing UTI necessitates gender-specific cut-off values, probably reflecting the influence of anatomical and urogenital differences.

Pharmacokinetic Properties of Micafungin in Critically Ill Patients Diagnosed with Invasive Candidiasis.

The estimated attributable mortality rate for invasive candidiasis (IC) in the intensive care unit (ICU) setting varies from 30 to 40%. Physiological changes in critically ill patients may affect the distribution and elimination of micafungin, and therefore, dosing adjustments might be mandatory. The objective of this study was to determine the pharmacokinetic parameters of micafungin in critically ill patients and assess the probability of target attainment. Micafungin plasma concentrations were measured to estimate the pharmacokinetic properties of micafungin. MIC values for Candida isolates were determined to assess the probability of target attainment for patients. Data from 19 patients with suspected or proven invasive candidiasis were available for analysis. The median area under the concentration-time curve from 0 to 24 h at steady state (AUC0-24) was 89.6 mg · h/liter (interquartile range [IQR], 75.4 to 113.6 mg · h/liter); this was significantly lower than the median micafungin AUC0-24 values of 152.0 mg · h/liter (IQR, 136.0 to 162.0 mg · h/liter) and 134.0 mg · h/liter (IQR, 118.0 to 148.6 mg · h/liter) in healthy volunteers (P = <0.0001 and P = <0.001, respectively). All Candida isolates were susceptible to micafungin, with a median MIC of 0.016 mg/liter (IQR, 0.012 to 0.023 mg/liter). The median AUC0-24/MIC ratio was 5,684 (IQR, 4,325 to 7,578), and 3 of the 17 evaluable patients (17.6%) diagnosed with proven invasive candidiasis did not meet the AUC/MIC ratio target of 5,000. Micafungin exposure was lower in critically ill patients than in healthy volunteers. The variability in micafungin exposure in this ICU population could be explained by the patients' body weight. Our findings suggest that healthier patients (sequential organ failure assessment [SOFA] score of <10) weighing more than 100 kg and receiving 100 mg micafungin daily are at risk for inappropriate micafungin exposure and potentially inadequate antifungal treatment. (This study has been registered at ClinicalTrials.gov under identifier NCT01716988.).

Synovial calprotectin: a potential biomarker to exclude a prosthetic joint infection.

AIMS: Recently, several synovial biomarkers have been introduced into the algorithm for the diagnosis of a prosthetic joint infection (PJI). Alpha defensin is a promising biomarker, with a high sensitivity and specificity, but it is expensive. Calprotectin is a protein that is present in the cytoplasm of neutrophils, is released upon neutrophil activation and exhibits anti-microbial activity. Our aim, in this study, was to determine the diagnostic potential of synovial calprotectin in the diagnosis of a PJI. PATIENTS AND METHODS: In this pilot study, we prospectively collected synovial fluid from the hip, knee, shoulder and elbow of 19 patients with a proven PJI and from a control group of 42 patients who underwent revision surgery without a PJI. PJI was diagnosed according to the current diagnostic criteria of the Musculoskeletal Infection Society. Synovial fluid was centrifuged and the supernatant was used to measure the level of calprotectin after applying a lateral flow immunoassay. RESULTS: The median synovial calprotectin level was 991 mg/L (interquartile range (IQR) 154 to 1787) in those with a PJI and 11 mg/L (IQR 3 to 29) in the control group (p < 0.0001). Using a cut-off value of 50 mg/L, this level showed an excellent diagnostic accuracy, with an area under the curve of 0.94. The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) was 89%, 90%, 81% and 95% respectively. The NPV was 97% in the nine patients with a chronic PJI. CONCLUSION: Synovial calprotectin may be a valuable biomarker in the diagnosis of a PJI, especially in the exclusion of an infection. With a lateral flow immunoassay, a relatively rapid quantitative diagnosis can be made. The measurement is cheap and is easy to use. Cite this article: Bone Joint J 2017;99-B:660-5.

PCR-based detection of Aspergillus fumigatus Cyp51A mutations on bronchoalveolar lavage: a multicentre validation of the AsperGenius assay® in 201 patients with haematological disease suspected for invasive aspergillosis.

OBJECTIVES: In patients with invasive aspergillosis (IA), fungal cultures are mostly negative. Consequently, azole resistance often remains undetected. The AsperGenius® multiplex real-time PCR assay identifies clinically relevant Aspergillus species and four resistance-associated mutations (RAMs; TR34/L98H/T289A/Y121F) in the Cyp51A gene. This multicentre study evaluated the diagnostic performance of this assay on bronchoalveolar lavage (BAL) fluid and correlated the presence of RAMs with azole treatment failure and mortality. METHODS: Stored BAL samples from patients with haematological diseases with suspected IA were used. BAL samples that were galactomannan/culture positive were considered positive controls for the presence of Aspergillus. Azole treatment failure and 6 week mortality were compared in patients with and without RAMs that had received ≥5 days of voriconazole monotherapy. RESULTS: Two hundred and one patients each contributed one BAL sample, of which 88 were positive controls and 113 were negative controls. The optimal cycle threshold cut-off value for the Aspergillus species PCR was <38. With this cut-off, the PCR was positive in 74/88 positive controls. The sensitivity, specificity, positive predictive value and negative predictive value were 84%, 80%, 76% and 87%, respectively. 32/74 BAL samples were culture negative. Azole treatment failure was observed in 6/8 patients with a RAM compared with 12/45 patients without RAMs (P = 0.01). Six week mortality was 2.7 times higher in patients with RAMs (50.0% versus 18.6%; P = 0.07). CONCLUSIONS: The AsperGenius® assay had a good diagnostic performance on BAL and differentiated WT from Aspergillus fumigatus with RAMs, including in culture-negative BAL samples. Most importantly, detection of RAMs was associated with azole treatment failure.

Routine tests and automated urinalysis in patients with suspected urinary tract infection at the ED.

BACKGROUND: Urinary tract infections (UTIs) are frequently encountered. Diagnostics of UTI (urine dipstick, Gram stain, urine culture) lack proven accuracy and precision in the emergency department. Utility of automated urinalysis shows promise for UTI diagnosis but has not been validated. METHODS: A total of 381 cases presenting with fever and/or clinically suspected UTI were analyzed. Diagnosis was based on clinical presentation, urine culture and/ or blood culture, and successful treatment. Performance of standard diagnostics and automated urinalysis (Sysmex UF-1000i) was analyzed at various cutoff values, and diagnostic algorithms were tested. RESULTS: One hundred forty-three (37.5%) cases were diagnosed with UTI. Sensitivity of urine dipstick nitrite was 32.9% and specificity was 93.7%. Sensitivity of urine dipstick leukocyte esterase (3+) was 80.4% and specificity was 82.8%. Receiver operating characteristic curves of automated bacterial and leukocyte count showed area under the curve of 0.851 and 0.872, respectively. Cutoff values of 133 bacteria/µL and 48 leukocytes/µL resulted in >90% sensitivity. Diagnostic values for complicated cases (antibiotics, catheters) were inferior to uncomplicated cases. Algorithms combining dipstick and automated counts did not improve accuracy with the exception of a 5.2% increase in uncomplicated cases (n=247). CONCLUSIONS: Automated leukocyte and bacterial count can be used in the emergency department setting with comparable accuracy compared with standard dipstick analysis with minor improvement when combined.

Evaluation of the Xpert vanA/vanB assay using enriched inoculated broths for direct detection of vanB vancomycin-resistant Enterococci.

Rapid and accurate detection of VRE (vancomycin-resistant enterococci) is required for adequate antimicrobial treatment and infection prevention measures. Previous studies using PCR for the detection of VRE, including Cepheid's Xpert vanA/vanB assay, reported accurate detection of vanA VRE; however, many false-positive results were found for vanB VRE. This is mainly due to nonenterococcal vanB genes, which can be found in the gut flora. Our goal was to optimize the rapid and accurate detection of vanB VRE and to improve the positive predictive value (PPV) by limiting false-positive results. We evaluated the use of the Xpert vanA/vanB assay on rectal swabs and on enriched inoculated broths for the detection of vanB VRE. By adjusting the cycle threshold (CT) cutoff value to ≤ 25 for positivity by PCR on enriched broths, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 96.9%, 100%, 100%, and 99.5% for vanB VRE, respectively. As shown in this study, CT values of ≤ 25 acquired from enriched broths can be considered true positive. For broths with CT values between 25 and 30, we recommend confirming the results by culture. CT values of >30 appeared to be true negative. In conclusion, this study shows that the Cepheid's Xpert vanA/vanB assay performed on enriched inoculated broths with an adjusted cutoff CT value is a useful and rapid tool for the detection of vanB VRE.

A before-after study of multi-resistance and cost of selective decontamination of the digestive tract.

BACKGROUND: We compared standard antibiotic use with an antibiotic policy based on selective decontamination of the digestive tract (SDD) for cost and microbiology. PATIENTS AND METHODS: A 2-year before-after observational study was performed in an 11-bed, mixed medical and surgical intensive care unit (ICU). We included all consecutive patients admitted to the ICU 1 year before and 1 year after institution of SDD (patients admitted within the 2-month SDD run-in period were excluded from analysis). In the year before SDD, 513 patients were treated in the ICU (mean APACHE II 19.5), compared to 529 in the year with SDD (mean APACHE II 19.4). RESULTS: The duration of mechanical ventilation was shorter in the SDD-treated patients (median 3, interquartile range [IQR] 2-7 days vs median 4 days, IQR 2-10, p = 0.03). The total of ICU variable costs, microbiological costs and antibiotic costs were equal in both episodes: euro 1,171 versus euro 1,168 per patient). Aerobic gram-negative bacilli (AGNB) and multiresistant AGNB were found less frequently in SDD-treated patients, RR 0.37 (95% CI 0.33-0.42) and RR 0.28 (95% CI 0.19-0.42). Multi-resistant AGNB in tracheal secretions and urine more than 72 hours after admission were completely absent in SDD-treated patients. CONCLUSION: The overall cost per patient treated during an antibiotic policy including SDD was equal to a policy supporting standard antibiotic care. In addition, duration of ventilation decreased and a trend was shown towards a decreased Length of ICU and hospital stay. Less frequently, cultures from organ sites containing AGNB were found during SDD and the number of multi-resistant strains was significantly reduced at organ sites, in particular trachea and urine. Fewer patients were colonized with multi-resistant AGNB but these numbers did not reach statistical significance.

[Diagnostic image (105). A woman with painful nodules. Infection with O. volvulus]. / Diagnose in beeld (105). Een vrouw met pijnlijke noduli. Infectie met O. volvulus.

A 17-year-old woman from the Democratic Republic of Congo presented with painful nodules on the legs and malaise. An infection with Onchocerca volvulus was diagnosed.

[Meningitis after a superficial dog bite]. / Meningitis na triviale hondenbeet.

A 63-year-old healthy man developed acute meningitis. A Gram-stain of the cerebrospinal fluid showed Gram-negative rods, which grew slowly. They were identified by 16S ribosomal RNA sequence-analysis as Capnocytophaga canimorsus, an oral commensal found in various animal species including dogs. Upon further questioning, the patient mentioned a superficial dog bite. Using fluorescence-in situ-hybridisation with specific DNA probes, C. canimorsus cells were detected in a gingiva swab from his dog. The strains isolated from the patient and his dog were identical. The patient made a quick recovery following therapy with cefotaxime. Infections with C. canimorsus are associated with immune suppression (especially splenectomy or alcohol abuse), yet 40% of the patients have no predisposing conditions. Documented infections concern mainly sepsis or meningitis, with a mortality of approximately 30%. Due to its fastidious growth, C. canimorsus may be missed in standard culture methods. Therefore, in each case of unexplained sepsis or meningitis contact with animals should be enquired about.

[Lambing ewes as a source of severe psittacosis in a pregnant woman]. / Lammerende schapen als bron van ernstige psittacose bij een zwangere.

The first documented Dutch case of an ovine Chlamydia psittaci infection concerned a 20-year-old woman in the 26th week of pregnancy, following contact with lambing sheep. She had a severe sepsis and had to be artificially ventilated. Finally, the patient made a full recovery. The preterm born child died directly after birth. The placenta showed an acute intervillitis in which chlamydial antigen was demonstrated immunohistologically. Infection with an ovine C. psittaci was confirmed by sequence analysis of amplified chlamydial DNA from the placenta. Infections with C. psittaci are typically associated with contact with (sick) birds. However, mammals also may act as a source of human infection, especially sheep in which C. psittaci is an important cause of abortion. Infections with ovine C. psittaci are a particular hazard for pregnant women, in whom there is severe placentitis and frequently foetal loss. Such infections are mainly associated with contact with lambing sheep.

Evolution of human immunodeficiency virus subtype A in women seroconverting post partum and in their offspring post-natally infected by ingestion of breast milk.

The evolution of genomic RNA of human immunodeficiency virus type 1 (HIV-1), subtype A, was studied in three Rwandan mother-child pairs over a period of 12-30 months. In two pairs a homogeneous subtype A V3 sequence population was observed at seroconversion and the virus populations in the children resembled those in the mothers. One of these mother-child pairs was infected with an A/C recombinant virus (Ap17/Cp24). In the third pair, a heterogeneous V3 sequence population was observed in the maternal seroconversion sample but the V3 sequence population in the child's sample was homogeneous. In each individual the intra- and intersample variation (between the seroconversion and follow-up samples) increased over time in both the V3 region and p17gag. Independent evolution for 1-2 years did not abolish the epidemiological relationship between virus populations in mother and child.

Primary infections with HIV-1 of women and their offspring in Rwanda: findings of heterogeneity at seroconversion, coinfection, and recombinants of HIV-1 subtypes A and C.

Variation in HIV-1 genomic RNA was studied in seroconversion samples from mother-child pairs from a Rwandan cohort. The mothers (n = 8) were heterosexually infected and their children (n = 6) were vertically infected by breast milk. Five of the children seroconverted within the same 3-month period as did their mothers. Highly homogeneous subtype A V3 and p17gag sequence populations were observed in three mother-child pairs, one of the two nontransmitting mothers, and one child (mean nucleotide distances 0 to 0.9%). Heterogeneous populations of subtype A V3 and p17gag sequences were found in one mother and a mother-child pair (1.4 to 2.8% for V3, 1.0 to 1.9% for p17). The second nontransmitting mother was infected with a heterogeneous AV1-V3/Cp17-p24 recombinant virus population (3. 8% for V3, 2.4% for p17). Finally, in one woman subtype C V3 sequences were observed, in addition to highly homogeneous subtype A V3 and p17gag sequence populations, also found in the child. Coexistence of subtype AV1-V3 and CV1-V3 env sequences in the mother was confirmed in a follow-up sample. The gag gene of both the maternal and the child's virus population represented an A/C recombinant sequence (Ap17/Cp24). An infection with subtype CV1-V3/p17-p24 was found upon testing of three additional participants of the mother-child cohort, indicating that subtype C is present in Rwanda. In conclusion, heterogeneity, coinfection, and intersubtype recombinants are not uncommon in primary HIV-1 infections in Rwanda.

Similarity in env and gag genes between genomic RNAs of human immunodeficiency virus type 1 (HIV-1) from mother and infant is unrelated to time of HIV-1 RNA positivity in the child.

Variation in the env (V3 region) and gag (p17 region) genes of genomic RNA of human immunodeficiency virus type 1 was studied in three mother-child pairs. One infant was human immunodeficiency virus type 1 RNA positive at birth (pair 114), one became positive 6 weeks after birth (pair 127), and one became positive 30 months after birth (pair 564). The first two children were born to seropositive mothers, and the last child was infected by breast-feeding following seroconversion of the mother after delivery. In both V3 and p17gag, intrasample variability was much higher in the maternal samples, including the first seropositive sample of the seroconverted mother, than in the infants' samples. Variability was less in p17gag than in V3, except in the postnatally infected child. In all three cases, infection of the child was established by variants representing a minority of the cell-free virus population in the maternal samples. For the two infants born to seropositive mothers, V3 sequences were more similar to the sequence populations of maternal samples collected during pregnancy than to those of samples collected at delivery or thereafter. However, in pair 114 a V3 variant identical to the child's virus was also detected in the sample collected at delivery. In contrast to the V3 region, p17gag sequences of maternal samples of the first trimester of pregnancy and at delivery had comparable resemblance to the child's sequences in pair 114, while in pair 127, similarity to sequences of the sample collected at delivery was higher than that to sequences of the sample from early in pregnancy. In the last pair, V3 and p17gag sequences from a maternal sample collected 18 months prior to the first RNA-positive sample of the child resembled the infant's sequences as much as the sample collected close to the presumed time of infection. Taken together, the evolutionary characteristics for genomic RNA env and gag genes did not point to a particular time of mother-to-child transmission.

Macrophage-tropic variants initiate human immunodeficiency virus type 1 infection after sexual, parenteral, and vertical transmission.

Macrophage-tropic, non-syncytium-inducing, HIV-1 variants predominate in the asymptomatic phase of infection and may be responsible for establishing infection in an individual exposed to the mixture of HIV-1 variants. Here, genotypical and phenotypical characteristics of virus populations, present in sexual, parenteral, or vertical donor-recipient pairs, were studied. Sequence analysis of the V3 domain confirmed the presence of a homogeneous virus population in recently infected individuals. Biological HIV-1 clones were further characterized for syncytium inducing capacity on the MT2 cell line and for macrophage tropism as defined by the appearance of proviral DNA upon inoculation of monocyte-derived macrophages. Both sexual and parenteral transmission cases revealed a selective outgrowth in the recipient of the most macrophage-tropic variant(s) present in the donor. In three out of five vertical transmission cases, more than one highly macrophage-tropic virus variant was present in the child shortly after birth, suggestive of transmission of multiple variants. In three primary infection cases, homogeneous virus populations of macrophage-tropic, non-syncytium-inducing variants were present prior to seroconversion, thus excluding humoral immunity as the selective pressure in favour of macrophage-tropic variants. These observations may have important implications for vaccine development.

Genomic human immunodeficiency virus type 1 RNA variation in mother and child following intra-uterine virus transmission.

In order to study the relationship between virus populations in a human immunodeficiency virus type 1 (HIV-1)-infected mother and her infant, we analysed a 276 bp fragment, including the V3 region, of genomic HIV-1 RNA purified from serum. Samples were collected from the mother 6, 4 and 2 months prior to delivery, during delivery and 10 months after childbirth (samples MA to ME, respectively) and from the infant at birth (cord blood) and the ages of 6 weeks and 9 months. A heterogeneous sequence population was observed in the maternal samples (mean nucleotide variation of 2.4 to 4.2%, range 0 to 8.3%). Until the age of 6 weeks the sequence population in the infant was highly homogeneous (mean nucleotide variation < or = 0.7%, range 0 to 2.5%). At 9 months of age, the infant's virus population showed more heterogeneity (mean nucleotide variation of 1.8%, range 0.4 to 3.6%) and a drift in the consensus sequence was observed. The evolution of the V3 region in the mother was characterized by accumulation of amino acid substitutions diverging from the virus population observed in the infant. The mean nucleotide distance between the maternal sequence populations and the sequence population of the child at birth was 2.8, 2.6, 3.7, 5.2 and 5.3% for the samples MA, MB, MC, MD and ME, respectively. Nearly complete replacement at position 308, previously described as antigenically important, from a proline to a histidine was observed during pregnancy, whereas all clones of the child's virus at birth and at 6 weeks contained a proline at that position. In conclusion, intra-uterine transmission is associated with a homogeneous sequence population in the child at birth, which is more closely related to the sequence population present in the mother during the first and second trimester of pregnancy than to the sequence population at delivery.

[HIV infection in pregnant women in The Netherlands]. / HIV-infectie bij zwangere vrouwen in Nederland.

A review is given of the pregnant women with HIV infection known to the co-ordinating centre of the 'Dutch prospective study of HIV seropositive pregnant women and their children'. Fifty-five women with 57 pregnancies were discovered between 1 September 1985 and 1 January 1991. Of these women, 60% were not of Dutch origin and 56% were living in Amsterdam. Thirty-two women were (former) intravenous drug users. In 23 women heterosexual transmission was likely; two women were also blood transfusion recipients. Nearly half (11/23) of these women came from, or had a partner from, an AIDS-endemic area. In 16 women HIV seropositivity was known before pregnancy. Twenty-four women were specifically tested during pregnancy or within 1 week after parturition because of risk factors for HIV infection. Fifteen women were discovered in a HIV screening programme of pregnant women in Amsterdam (n = 13) and the University Hospital of Groningen (n = 2). At first, eight of these women did not mention risk factors. Thirty-five women could choose abortion (less than or equal to 20 weeks of gestation); the majority (69%) decided to continue pregnancy. Twelve pregnancies ended in an elective or spontaneous abortion, 39 in the birth of 40 children (one pair of twins) of whom 39 were viable, three women were still pregnant and of three the pregnancy outcome was unknown. Preterm delivery (8/39) and birth weight less than 2500 gram (7/39) were seen frequently, the latter particularly in women (formerly) using intravenous drugs (6/25).